docs: def save(self, sender):
          """
          Save the message and send it out into the wide world.
  
          :param sender:
              The :class:`User` that sends the message.
  
          :param parent_msg:
              The :class:`Message` that preceded this message in the thread.
  
          :return: The saved :class:`Message`.
  
          """
          um_to_user_list = self.cleaned_data['to']
          body = self.cleaned_data['body']
  
          msg = Message.objects.send_message(sender,
                                             um_to_user_list,
                                             body)
  
          return msg